The last time that I fished the SoHo, I had very good success in the early hours using a size 16 pheasant tail emerger pattern in the seam lines. Later in the afternoon, it was overcast with a little precipitation which sparked the most epic hatch of BWO’s I have ever seen. What was working the best during this hatch was size 20 and 22 thread body BWO dries. These were so small I had trouble seeing them on the water; I had to tie on a size 14 and trail it with the smaller bug and watch for a strike around the larger bug I was using as the indicator. There was also a good number of Sulphurs size 14-16 coming off as well, the pattern I was using apparently was not a close enough match, I kept getting rejected so I stuck with the BWO pattern.
Good luck to you.
God gave fishermen expectantcy so they would never tire of throwing out a line.